Re: Your help needed

[Bill Allombert <allomber@math.u-bordeaux.fr>]

On Tue, Jan 28, 2014 at 08:05:27AM +0900, SeongHan Shin wrote:
> Dear Bill,
> 
> >I assume you want to compute the order of a point on a elliptic curve
> >over a finite field of size around 512bit.
> >Unfortunately the number of points on the curve is too hard to be factored
> >by PARI.
> Yes, that's exactly what I want to do.
> Is there any way to compute a 512-bit order?

Not unless you know the factorisation of the order of the elliptic curve, or
some similar useful information

Cheers,
Bill.